Draftsman s rule



P. W.'ALTPETER.'

DRAFT'SMAN'S RULE,

( o Model.)

No. 530,741. Patented Dec. '11, I894.

w v v LEE UNITED STATES OFFICE.

FRANCIS WALTER ALTPETER, OF CHICAGO, ILLINOIS.

DRAFTSMANS- RULE.

SPECIFICATION forming partof Letters-Patent No. 530,741, dated December 11, 1894. Application filed April 5,1894; Serial itmoasve'. momma) To all whom it may concern.-

Be it known that I, FRANCIS WALTERAL'T PETER, a citizen of theUnited States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Draftsme'ns' Rules; and I do declare thefollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in' the art to which it appertains to make and use the same, reference beinghad to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

My invention relates to adjustable rules for view of my improved rule extended as a straight edge, on a scale of one-half inch to the inch; Fig. 2, a similar view, the joint being broken to bring one member into perpendicular relation as to the other. Figs. 3 to 7, inclusive, are details of the joint. Fig. 8, is a plan view of the rule folded; and Fig. 9, is a bottom plan of adjacent ends of the two members, in full size.

The two members, A, B, of the rule are shown as of equal length and width and one of its edges beveled and provided with a scale of linearinches, its other edge being vertical.

Member, A, has a longitudinal channel along its upper surface, the channel having an in-,

wardly projecting flange, or lip, on each side. A screw threaded stud, E, having an elongated T-head, e, is carried in this channel, being adapted to slide freely therein. An apertured block, D, is pivotally attached to the member, B, by the pin, d, near one of its ends. An arm, C apertured at one end to fit loosely upon the stud, E, and having its other end fitted loosely within the aperture of the block; D, unites the two members, A, B. The arm C, is secured within the block, D, by means of the pin, 0, fixed transversely across the aperture of the block and extending through a'longitudinal slot in the arm, a spiral spring, 0, reacting between the pin, 0, and the outer end of'the arm so as to normally draw A nut, F, fits upon the stud, E, and when turneddown draws the arm, 0, firmly'against thesu'rfaceof the member, A, and the block,

1e, against the flanges of its channel thereby preventing the stud from'being moved within the channel. Ajam nut, f, maybe employed to prevent the accidental turning of the nut, F. The inner end of the member, B, is'concave as shown at b, and the vertical edge of the member, A, has a concave recess, a, near its inner end.

When the rule is straight, as shown in Fig. 1, a pin, 70, set in the inner end of the member, A, nearits beveled edge, engagesa socket correspondingly located in the adjacent end of the member, B. The rule is thereby prevented from having its joint broken without the application of longitudinal strain to the two members in opposite directions for the purpose of separating them by.compressing the spring, 0'. When the member, B, is released from engagement with the pin, is, it is readily turned on the stud E,and the recess, b, facilitates this movement. When in the position shown in Fig. 2, the member, B, being perpendicular to the member, A, the former will readily slide upon the latterif the nut, E, is loose, and the tool is now a con venient instrument for drawing parallels, as in section lining.

The two members are folded together in the position shown in Fig. 3. Bycarrying the member, B, when perpendicular to the member, A,

to the inner end of the latter when its vertical edge is over the recess, a, the member,'B, turns upon its pivot pin, cl. A stud pin, it, set in the vertical edge of the member, A, engages a socket indicated at k, correspondingly located in the member, B, and prevents the one sliding upon the other.

The pin, 01, is formed with a recess in its outer end so that its edges may be flared out by the use of a suitable tool, thereby locking it within its aperture. The arm, 0, is formed with an ofi-set to bring its outer-end against the surface of the member A.

Usually the nut, F, will not be turned down so as to bind upon the arm, O,but will merely be brought into frictional contact with it, and locked in that position by the jam nut, f. The tension of the spring, 0', will be sufficient to prevent the member, B, from being readily displaced when in its angular position.

I claim as my invention- 1. The combination in a draftsmans rule, of the two members, A, B, the member A having a longitudinal channel with contracted opening, a T-headed stud, E, projecting outwardly and adapted to slide in the channel, and a spring retracted extensible arm for uniting the two members and being pivoted to the member, B, and apertured to receive the stud, E,substantially as described and for the purpose specified.

2. The combination, in a draftsmans rule, of a member, A, having a longitudinal channel with contracted opening, a block adapted to slide within the channel, a stud E, set in the block and projecting outwardly through 3. The combiuatiomin a draftsmans rule, of two members, A, B, adapted to co-operate end to end, or the one perpendicular to the other, of a spring retracted arm for uniting the two members, said arm being pivoted to one member by a fixed pin and to the other by meansof a pin adapted to move longitudinally upon said member, substantially as de scribed and for the purpose specified.

4. In an adjustable draftsmans rule, the combination with the member A, having a square end and a concave recess in one of its edges near such end, of a member, B, a spring retracted arm for uniting the two members and being pivoted to the member, B, at a fixed point and to the member, A, by a movable pin, whereby the end of the member, B, may be held in contact with the recessed edge of the member, A, said recess allowing the member, B, to be turned to bring its edge against the edge of the member, A, substantially as described and for the purpose specified.

5. The combination, in a draftsmans rule, of two members, A, B, adapted to co-operate end to end or the one perpendicular to the other, of a spring retracted arm, C, for uniting the two members, said arm being pivoted to the member A, a socketed block attached to the member B, the arm 0 being adapted to slide within such socket, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

F. WALTER ALTPETER.

Witnesses:

LoUIs K. GILLSON, MAY H. L. WING. 

